API folder not hidden

According to this little JSON API recipe (https://getkirby.com/docs/cookbook/json), the api folder should be hidden, however it is not. Any way I can keep this out of the admin panel?

If you want to hide it from the Panel, create a blueprint with the same name as the text file and add

hide: true

to it.

Hidden folder only means, that it has no number. It’s just a flag.